Iron-Promoted Elimination of β-Thioalkoxy Alcohols. Olefination by Coupling of a Carbonyl Group with a Dithioacetal
摘要:
Treatment of propargylic dithiolanes with (BuLi)-Bu-n followed by a carbonyl electrophile yields the corresponding propargylic dithioacetals. Upon treatment with 1 equiv of Fe(acac)(3) and excess MeMgI, elimination of SR and OH moieties from 8 affords the corresponding olefins in satisfactory yield. Benzylic dithioacetals behave similarly. The reaction can be considered an alternative of McMurry coupling of two different carbonyl equivalents.
Iron-Promoted Elimination of β-Thioalkoxy Alcohols. Olefination by Coupling of a Carbonyl Group with a Dithioacetal
摘要:
Treatment of propargylic dithiolanes with (BuLi)-Bu-n followed by a carbonyl electrophile yields the corresponding propargylic dithioacetals. Upon treatment with 1 equiv of Fe(acac)(3) and excess MeMgI, elimination of SR and OH moieties from 8 affords the corresponding olefins in satisfactory yield. Benzylic dithioacetals behave similarly. The reaction can be considered an alternative of McMurry coupling of two different carbonyl equivalents.
Elimination of β-Thioalkoxy Alcohols under Mitsunobu Conditions. A New Synthesis of Conjugated Enynes from Propargylic Dithioacetals
作者:Chih-Wei Chen、Tien-Yau Luh
DOI:10.1021/jo8013885
日期:2008.11.7
Treatment of propargylic dithiolanes 1 with (n)BuLi followed by a carbonyl electrophile yields the corresponding homopropargylic alcohol 3. Upon treatment with 2 equiv of PPh3 and DIAD, elimination of SR and OH moieties from 3 affords the corresponding olefins 4 in moderate to good yield. The reaction can be considered an alternative of McMurry coupling of two different carbonyl equivalents.
A Convenient Synthesis of Tetrasubstituted Furans from Propargylic Dithioacetals
作者:Tien-Yau Luh、Jui-Chang Tseng、Jia-Hong Chen
DOI:10.1055/s-2006-939686
日期:——
A convenient procedure for the regioselective synthesis of tetrasubstituted furans from the corresponding propargylic dithioacetals is described. Treatment of propargylic dithioacetals with n-BuLi and an aldehyde followed by mercuric acetate promoted annulation and desulfurization affords the corresponding mercurio-substituted furans. Subsequent replacement of the mercury moiety with iodine yields the corresponding 2,4,5-trisubstituted 3-iodofurans. Transition-metal-catalyzed cross-coupling reactions of the iodofurans furnish a variety of tetrasubstituted furans.
Mercuric acetate-mediated annulation of homopropargylic alcohols having thioether substituent. A general route for the synthesis of tetrasubstituted furans from propargylic dithioacetals
作者:Chih-Wei Chen、Tien-Yau Luh
DOI:10.1016/j.tetlet.2009.02.043
日期:2009.7
Treatment of an alkyl-substituted propargylic dithioacetal with (BuLi)-Bu-n followed by an aldehyde furnishes thio-substituted homopropargylic alcohol 7 which undergoes annulation in the presence of two equivalents of mercury acetate to give the corresponding mercurio-substituted furan 12. Reaction of 12 with iodine gives iodofuran in moderate to good yield. (C) 2009 Elsevier Ltd. All rights reserved.